The present invention relates to a method and a device for braking vehicles, in particular racing vehicles at the edge of a racetrack.
It is customary when racing vehicles to provide devices that can brake the vehicles or absorb their impact at critical locations where there is a risk of the race cars departing from the racetrack. To do so, at a critical curve at the edge of the racetrack, a gravel bed, for example, is provided, followed by a wall of tires consisting of several rows of stacked tires. However, these measures are not sufficient to reliably ensure that in the event of a brake failure, for example, the vehicle will be adequately braked because it still strikes the wall of tires at a high speed and the driver may still suffer considerable injuries due to the stable concrete wall behind the tires.
German Patent Application No. 4,418,554 A1 describes a device for securing hazardous areas of a racetrack, where movable barriers are provided to absorb and dissipate the kinetic energy of a vehicle that departs from the track. The barrier is made of flexible, interconnected elements which are flexibly connected to the ground in a form-fitting manner. To do so, rails are driven into the ground so that tires arranged perpendicularly, i.e., with the tread down, can move in them. Since the barrier is arranged at a curve, the running rails are not arranged in parallel in the ground, but instead they are spread apart. Therefore, the tires are connected by an elastic band to be able to absorb the spreading effect when struck by a vehicle. The two ends of the barriers are fixedly anchored by a flexible band and thus allow only expansion of the barrier. Due to such a design, the kinetic energy is converted into energy of tension, so that a catapulting effect can be expected at the end of the running rails. With a reverse movement, there is a risk of jamming. When a vehicle strikes the barrier, only one running rail, namely the one in the direction of travel, can be loaded properly, while the others are loaded at an inclination, ant thus the elastic band can be stressed only in a partial range. Thus, the kinetic energy of the vehicle must be absorbed by a relatively small number of elastic bands. This causes an enormous lack of safety. On the whole, the device disclosed here presents an impractical solution from the standpoint of safety, assembly and cost.
German Patent Application No. 4,418,554 A1 describes a safety device for vehicle borders for use in motorcycle racing, where the stacks of horizontal tires are used to reduce the frontal impact against a barrier, divert it and prevent the vehicle from being stuck on the barrier. The tire stack is therefore provided with a crash barrier of plastic tubing and attached to slightly curved concrete barriers. This solution is similar to that already discussed above and the tire stack wall customary in the past and it is not suitable for braking a vehicle traveling at a high speed.
Austrian Patent 372,443 B describes a noise abatement wall consisting of stacks of tires that can be planted with greenery. Two rows, one above the other, are connected by screws, and any unwanted movement of the noise abatement wall is prevented by perpendicular iron rods or tubes driven into the ground. This proposal for a noise abatement wall is not suitable for use as a device for braking vehicles in racing.
German Patent Application 3,308,651 A1 describes a network of tire-like bodies for which used tires in whole form or preferably in chopped form can be used. This network serves as a fence for protecting people, animals and objects. Posts with the network stretched between them are provided. This network is anchored rigidly in the ground and its effect should be inferior to that of the tire stacks described above with regard to safety for racing.
U.S. Pat. No. 5,645,368 describes a barrier of two rows of barrier modules of tire stacks arranged horizontally one above the other with an offset, connected by iron clamps between a base plate and a cover plate. The base plate has the advantage that these barrier modules for racing can easily be arranged at the respective locations where there is a risk for the race car drivers, and they can easily be moved by the impact. This barrier is also used to mark the course of the racetrack.
U.S. Pat. No. 3,951,384 discloses a formable absorption device consisting of stacks of tires connected by bands, anchored to the bottom and stacked on top of each other. To increase the absorption capacity, the inside of the tires is filled with empty, fragile containers such as plastic bottles or metal cans. These tire stacks are positioned in front of a wall.
U.S. Pat. No. 5,480,255 also describes a wall of tires stacked over one another with an offset in essentially two rows, with the interspaces filled with sand to function as a crash wall for speedways. The tires themselves can also be connected to one another. This crash wall is also fixedly anchored in the ground and resembles the other options described above.
The situation is similar with U.S. Pat. No. 5,056,961, where tires are again used to construct walls by stacking them above one another and connecting them to one another.
International Patent WO 98/06904 A also describes an essentially known system for arranging stacks of tires to protect the race car driver from obstacles such as trees, posts, bridge pillars, walls or the like. Here again, the individual tires are linked together by bands and are secured to the ground or other suitable locations.
As practice has shown, none of these measures are suitable for braking a vehicle traveling into the tire wall at a high speed without causing severe damage to the vehicle and a high risk of injury to the driver.
Therefore, the object of the present invention is to propose a method that will permit reliable braking of the vehicles without greatly endangering the vehicle or the driver.
This object is achieved according to this invention by a method and by a safety wall having the features described hereinbelow.
According to this invention, the vehicle is braked by arranging an elastic, chain-like safety wall consisting of individual elements linked together movably at a clearance adjacent to the racetrack, and a vehicle leaving the racetrack and colliding with the safety wall is braked due to the elastic movement of the safety wall. Due to the arrangement of a free-standing safety wall consisting of individual elements linked together so that they can still move, without being anchored in the ground and with sufficient clearance behind the vehicle, a vehicle penetrating into the safety wall will entrain the wall and thus be braked by it because of the mass of the safety wall. It has surprisingly been found that the vehicle is then braked linearly to a standstill, so that no injury to the driver need be expected. Depending on the design, damping in addition to friction or instead of friction can occur due to damping elements arranged at the end of the safety wall and fixedly anchored there, permitting free movement of the safety wall as such but also damping its motion until it stops. To minimize the loads in impact of a vehicle with the safety wall, the inherent weight of the individual elements should be minimized, and the individual elements must also be elastic. This greatly reduces the intensity of the impact. According to a preferred embodiment, passenger vehicle tires are used as these elements, because they have the required properties and they are also available in abundance.
According to the safety wall designed according to the present invention, the safety wall has elastic, movable safety wall elements that are linked together like a chain and preferably have a total height greater than the height of the race car vehicle. The individual safety wall elements, preferably automobile tires, may be arranged as individual stacks of tires and linked together so they can still move. According to a preferred embodiment, the safety wall elements are stacked in an intermeshed arrangement and are movably connected to one another at the points of contact, because the number of safety wall elements and the inherent weight of the individual elements can be kept as low as possible in the area of a possible impact through this staggered arrangement.
On the whole, a sufficient weight on the order of the weight of the race car vehicle is achieved due to the length of the safety wall, which extends far beyond the critical location where the vehicle could leave the track, and this weight of the safety wall is sufficient to reliably brake a vehicle which runs off the track and collides with the safety wall.
To prevent the vehicle from rising above the safety wall or passing beneath it, a final band which connects all the stacks is arranged on the lowest elements near the bottom, so that when a race car vehicle collides with the safety wall, its front part passes over this band and thus reliably prevents the tire wall from lifting up in the remaining course of the braking process. In addition, the ends of the safety wall are advantageously connected to a fixed anchor, preferably being anchored to the ground, in order to prevent a whipping effect where the ends whip against one another due to the movement.
The individual safety wall elements can also be linked together by cords that have sufficient tensile strength to withstand the respective loads or by other suitable connecting means.
The present invention thus permits an inexpensive design of a safety wall by using available objects, resulting in a linear and soft retardation of the vehicle at the same time. This makes a considerable contribution toward the safety of the race car driver.